Capsule having a rupture initiation area

ABSTRACT

The invention relates to a capsule having a body in the form of a cup and a membrane lid, together defining a chamber containing a substance for the preparation of a drink. The body includes an outer substantially frusto conical side wall and a base integral with the outer side wall and closing said outer side wall at a rear end of the body. The membrane lid closes the other end of the outer side wall. The base is formed by a peripheral region defining the rear end of the body and by a central region extending into the capsule in relation to the rear end, defining a recess outside the body. The central region includes at least one weakened area which is intended to break at least partially under the pressure of a pressurized liquid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and is the National Stage of International Application No. PCT/FR2011/051320, filed Jun. 9, 2011, which also published as WO 2011/154665 on Dec. 15, 2011. Further, this application claims priority to French Application Nos. 1054651, 1054652, and 1054653, all filed Jun. 11, 2010, and European Application Nos. 10306432.5 and 10306436.6, both filed Dec. 16, 2010. All of the above applications are incorporated herein by reference.

BACKGROUND

The present invention relates to a capsule for extracting a beverage under pressure, of the type comprising a cup shaped body and a membrane lid together defining a chamber containing a substance for the preparation of a beverage, the body comprising a substantially frusto conical outer side wall and a base formed integrally as one piece with the outer side wall and closing said outer side wall at a rear end of the body, the membrane lid closing the outer side wall at the front end of the body, the capsule being adapted so as to be disposed in an extraction device in a manner such that an extraction liquid under pressure enters into the capsule through the base and exits from it through the membrane lid.

FR 2 373 999 discloses such a capsule for use in a beverage extraction device, in order to produce a beverage such as coffee.

There is a risk that such a capsule could collapse upon closure of the device for extracting a beverage and/or of the injection of the pressurized liquid.

In addition, these capsules are particularly expensive to produce, especially when they are produced in large batches.

Finally, when such a capsule is used in an extraction device comprising of a housing cavity for holding the capsule and a support against which the capsule is applied, the membrane lid is pressed against the support, thereby preventing a satisfactory flow of the liquid through the capsule.

An object of the invention is to provide a capsule that makes it possible to limit the risk of collapsing while enabling the extraction of a beverage. Other objects of the invention are to provide a capsule that may be easily calibrated so as to adjust the pressure level at which the extraction liquid enters the capsule, to offer a low cost capsule, and to provide a capsule that is compatible with many beverage extraction devices.

SUMMARY

To this end, a first example of the invention relates to a capsule of the aforementioned type, wherein the base is formed by a peripheral region defining a rear end of the body, and a central region returning towards the interior of the capsule in relation to the rear end while defining a recess on the outside of the body, the central region comprising at least one weakened area which is meant to rupture at least partially under the pressure of a pressurized liquid.

According to other embodiments, the capsule includes one or more of the following characteristics, considered alone or in accordance with any technically feasible combination(s):

-   -   the central region includes a bottom portion and a central stud         protruding from the bottom portion towards the exterior,     -   the central region includes an annular rib protruding towards         the interior of the body, the recess having the shape of an         annular trench on the exterior of the body,     -   the central region includes a flat bottom portion axially         closing the recess,     -   the or each weakened region is formed in the bottom portion,     -   the base includes at least one rib for reinforcing the central         region,     -   the body includes at least one radial rib for stiffening the         peripheral region,     -   prior to the rupture of the or each weakened area, the base and         the outer side wall of the body are impermeable to air and         liquid,     -   the central stud has a frusto conical shape,     -   the central stud has a hemispherical shape,     -   the membrane lid includes a filter and a membrane,     -   the filter is set back from the front end of the body, towards         the chamber, the membrane extending along the front end,     -   the space between the filter and the membrane is filled with         nitrogen,     -   the membrane is peelable,     -   the outer side wall and the base are formed of a first plastic         material, and the body includes an annular flange extending         radially outward towards the exterior from the outer side wall         and defining the front end of the body, said annular flange         being formed of a second plastic material, different from the         first plastic material,     -   the central region includes a tubular outer portion extending         axially towards the interior of the chamber from the peripheral         region, the or each weakened area being formed at the junction         between the bottom portion and the outer portion,     -   the or each weakened area is adapted so as to rupture from the         pressure of the liquid being pressurized to between 1 and 3         bars.

A second example of the invention relates to a capsule for extracting a beverage under pressure, of the type comprising of a cup shaped body and a membrane lid defining a chamber containing a substance for the preparation of a beverage, the body comprising a substantially frusto conical sidewall and a base which is formed integrally as one piece with the side wall and closing the side wall at one end, the membrane lid closing the other end of the side wall, the capsule being adapted so as to be disposed in an extraction device in a manner such that an extraction liquid under pressure enters into the capsule through the base and exits from it through the membrane lid, characterized in that the base has a central region having an annular rib for reinforcement of the base protruding towards the interior of the body and defining an annular trench on the exterior of the body.

According to other embodiments, said capsule includes one or more of the following characteristics, considered alone or in accordance with any technically possible combination(s):

-   -   the central region has at least one weakened area which is meant         to rupture at least partially under the pressure of a         pressurized liquid;     -   the annular rib has a ‘U’ shaped section defined by two lateral         portions connected by a base, with at least one weakened area         being defined in the base;     -   the annular rib defines a central stud surrounded by the annular         trench, the central stud comprising at least one weakened area;     -   the base includes a rounded peripheral region with its concave         side facing towards the interior of the body;     -   the base and the side wall of the body are air tight and water         tight;     -   the body has an annular flange extending radially outward         towards the exterior from the side wall, the flange defining an         end of the capsule that is opposite to the base;     -   the membrane lid includes a filter;     -   the membrane lid includes a membrane that is impermeable to air         and water, and     -   the membrane is provided with lines of weakness for opening of         the membrane under the effect of only the pressure of a         pressurized fluid.

A third example of the invention relates to a capsule for extracting a beverage under pressure, of the type comprising of a cup shaped body and an outlet filter defining a chamber containing a substance for the preparation of a beverage, the capsule comprising an impermeable outlet membrane, the body comprising a base defining a rear end of the body and a substantially frusto conical side wall extending from the base up to an open front end of the body, the membrane closing the front end, the capsule being adapted so as to be disposed in an extraction device in a manner such that an extraction liquid under pressure enters into the capsule through the base and exits from it through the outlet membrane, characterized in that the filter and the membrane are positioned so as to be set back in relation to the front end of the body.

According to other embodiments, said capsule includes one or more of the following characteristics, considered alone or in accordance with any technically possible combination(s):

-   -   the sidewall includes an internal shoulder that is set back in         relation to the front end of the body, the filter and the         membrane being secured to the internal shoulder;     -   the outlet membrane is set back in relation to the front end by         a distance that is greater than 1 mm;     -   the outlet membrane is impermeable to air and water;     -   the outlet membrane is so adapted to tear under the effect of         the sole pressure of a liquid, in a manner so as to allow the         outflow of a liquid passing through the capsule;     -   the outlet membrane includes at least one line of weakness;     -   the outlet filter is disposed between the chamber and the outlet         membrane;     -   the filter and the outlet membrane are joined to each other;     -   the outlet filter is made of plastic material that is woven or         perforated; and     -   the membrane is a film made of a material that is plastic or         metal, in particular aluminum.

A fourth example of the invention relates to a system comprising of a capsule according to the first, the second or the third example of the invention, and an extraction device having a housing meant for holding the capsule, a support and a conduit for supplying the extraction liquid.

-   -   A fifth example of the invention concerns a system of the type         having a device for the extraction of the beverage and a capsule         for the extraction of a beverage under pressure, the capsule         including a cup shaped body and a membrane lid defining a         chamber containing a substance for the preparation of a         beverage, the body including a substantially frusto conical side         wall and a base closing the side wall at one end, the membrane         lid closing the other end of the side wall, the capsule being         adapted so as to be disposed in an extraction device in a manner         such that an extraction liquid under pressure enters into the         capsule through the base and exits from it through the membrane         lid, the beverage extraction device including a member for         receiving a capsule having an inner side face, characterized in         that the capsule is so adapted in order for the base to make         contact against the receiving member along a closed annular         contact line.

According to other embodiments, the system includes one or more of the following characteristics, considered alone or in accordance with any technically possible combination(s):

-   -   the capsule and the receiving member are configured so that the         receiving member exerts a compressive force on the base of the         capsule, the base and/or the side wall of the capsule being         adapted so as to deform under the effect of this force;     -   the side wall and/or the base of the body expands radially under         the effect of the force exerted by the receiving member of the         extraction device, in a manner so as to ensure a contact between         the side wall of the body of the capsule and the inner side face         of the receiving member;     -   the base of the body of the capsule includes a rounded         peripheral region with its concave side facing towards the         interior of the body;     -   the base of the capsule includes an annular peripheral region         and a central region including an annular trench, with the line         of contact being defined on the peripheral region;     -   the line of contact is defined by an outer edge of the trench at         the junction between the trench and the peripheral region;     -   the outer edge of the trench is angular;     -   the body of the capsule includes an annular flange at the end of         the side wall that is opposite to the base, the annular flange         being at least partly inclined towards the front of the capsule,         on the side opposite to the base;     -   the flange of the capsule body is frusto conical widening         towards the front; and     -   the flange of the capsule body is curved forward towards the         front.

A sixth example of the invention relates to a capsule for extracting a beverage under pressure, of the type including of a cup shaped body and a membrane lid defining a chamber containing a substance for the preparation of a beverage, the body including a substantially frusto conical sidewall and a base closing the side wall at a first end, the membrane lid closing the second end of the side wall, the capsule being adapted so as to be disposed in an extraction device in a manner such that an extraction liquid under pressure enters into the capsule through the base and exits from it through the membrane lid, characterized in that the capsule is so adapted in order for the base to make contact against a capsule receiving member of an extraction device, along a closed annular contact line.

According to other embodiments, said capsule includes one or more of the following characteristics, considered alone or in accordance with any technically possible combination(s):

-   -   the capsule is designed so that, when an axial force is applied         to the base of the body, at least one annular region of the         sidewall and/or of the base expands radially outwards towards         the exterior;     -   the base of the body of the capsule includes a rounded         peripheral region with its concavity facing towards the interior         of the body;     -   the base is adapted so as to deform under the effect of a force         exerted axially on the latter;     -   the base of the capsule includes an annular peripheral region         and a central region including an annular trench, with the line         of contact being defined on the peripheral region;     -   the line of contact is defined by an outer edge of the trench,         at the junction between the trench and the peripheral region;     -   the outer edge of the trench is angular;     -   the body of the capsule includes an annular flange at the end of         the side wall that is opposite to the base, the annular flange         being at least partly inclined towards the front of the capsule,         on the side opposite to the base;     -   the flange of the capsule body is frusto conical widening         towards the front;     -   the flange of the capsule body is curved forward towards the         front; and     -   the body is made integrally as a single piece out of plastic         material or material derived from plastic, or metal.

Finally, the seventh example of the invention relates to an extraction process using a system according to the fifth example of the invention, characterized in that the method includes the following steps:

-   -   installation of the capsule in the beverage extraction device;     -   application, by the member for receiving the extraction device,         of a force on the base of the capsule;     -   deformation of the base and/or the side wall of the capsule         body, a part of the base and/or the side wall making contact         along a closed line with the member for receiving the extraction         device; and     -   injection of the extraction liquid into the capsule by means of         injection of the liquid from the extraction device.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood upon reading the description that will follow given purely by way of example and with reference being made to the attached drawings, in which:

FIG. 1 shows a view in perspective of a first variant of a capsule according to a first embodiment of the invention;

FIG. 2 is a longitudinal cross sectional view of the capsule in FIG. 1;

FIG. 3 is a front view of the capsule in FIG. 1;

FIGS. 4 and 5 are views of the capsule in FIG. 1, installed in an extraction device in configurations that are respectively partially open and closed;

FIG. 6 is a longitudinal cross sectional view of a second variant of the capsule according to the first embodiment;

FIG. 7 is a longitudinal cross sectional view of a third variant of the capsule according to the first embodiment;

FIG. 8 is a view of the capsule in FIG. 6, as installed in an extraction device in a closed configuration;

FIG. 9 shows a view in perspective of a first variant of a capsule according to a second embodiment of the invention;

FIG. 10 is a longitudinal cross sectional view of the capsule in FIG. 9;

FIG. 11 is a rear view of the capsule in FIG. 9;

FIG. 12 is a view of a detail marked XII in FIG. 10;

FIG. 13 is a view of a detail marked XIII in FIG. 10;

FIG. 14 is a view of the capsule in FIG. 8, as installed in a first extraction device in a closed configuration;

FIG. 15 is a view similar to that in FIG. 14, with the capsule being installed in a second extraction device in a closed configuration;

FIG. 16 is a longitudinal cross sectional view of a second variant of a capsule according to the second embodiment;

FIG. 17 is a view of a detail marked XVII in FIG. 16;

FIG. 18 is a rear view of a third variant of a capsule according to the second embodiment;

FIG. 19 is a rear view of a fourth variant of a capsule according to the second embodiment;

FIG. 20 is a rear view of a fifth variant of a capsule according to the second embodiment;

FIG. 21 is a rear view of a sixth variant of a capsule according to the second embodiment, and

FIG. 22 is a rear view of a seventh variant of a capsule according to the second embodiment.

DETAILED DESCRIPTION

The capsule 1 according to a first embodiment of the invention, represented in FIGS. 1 to 3, includes a hollow body 4 and outlet membrane lid 6 together defining an interior chamber 8 containing a substance (not shown) for the preparation of a beverage.

The body 4 has a generally cup shaped form and includes a side wall 10, a base 12 closing a closed rear end 20 of the body 4, and an annular flange 16 surrounding an open front end 22 of the body 4.

The body 4 is made integrally as a single piece. The side wall 10, the base 12 and the annular flange 16 are formed integrally as one piece. The body 4 is made of a material that is impermeable to air and water, for example of a plastic material or a material derived from plastic, or metal.

The side wall 10 extends from the base 12 along a longitudinal axis X to the front end 22 of the body 4.

The sidewall 10 includes an internal shoulder 14. The shoulder 14 extends in a radial plane and is oriented towards the front.

The side wall 10 is substantially rotationally frusto conical about the longitudinal axis X. The side wall 10 includes a rear section 18 that is relatively flexible, extending from the base 12 and a front portion 19 that is relatively rigid, axially extending the rear section 18. The front section 19 has an axially increasing thickness, which is greater than that of the rear section 18.

The base 12 has a peripheral region 23, extending radially inward towards the interior from the side wall 10, and a central region 24.

The peripheral region 23 is rounded. It extends inwards radially towards the interior and axially rearwards towards the rear, from the side wall 10, and has a concavity facing towards the interior of the body 4.

The central region 24 includes an annular rib 26 protruding axially towards the interior of the body 4 from the peripheral region 23. The annular rib 26 defines an annular trench 28 open to the exterior of the body 4 towards the rear. The annular rib 26 defines a hollow central stud 30 protruding axially from the bottom of the annular trench 28 while defining a recess within the interior of the body 4.

The central region 24 has at least one weakened area 32 provided in order to break under the effect of a pressurized fluid. The weakened areas 32 are provided, for instance, in the form of areas of reduced thickness of the central region 24, for example, defined by indentations formed in the central region 24.

The weakened areas 32 are provided in the walls of the annular rib 26 and/or on the central stud 30.

In the illustrated example, the annular rib 26 includes a tubular outer portion 36 extending axially towards the interior from the peripheral region 23, a tubular inner portion 34 defining a lateral face of the central stud 30 and a bottom portion 38 extending radially between the outer portion 36 and the inner portion 34 while giving the annular rib 26 a cross section substantially in the shape of a “U”.

As shown in FIG. 2, the weakened areas 32 are provided in the bottom portion 38 and in the central stud 30 in the form areas of reduced thickness.

As a variant, the central region 24 is devoid of weakened areas 32 in the central stud 30. As a variant or optionally, the annular rib 26 has weakened areas 32 in the outer portion 36 and/or in the inner portion 34.

In another possible variant that differs from the one in FIG. 2 by the shape of the annular rib 26, the outer portion 36 and the inner portion 34 converging by giving the annular rib 26 a cross section substantially in the shape of a V. In this case, the weakened areas 32 may be provided in the outer portion 36, the inner portion 34 and/or the central stud 30.

As shown in FIG. 2, the annular trench 28 has an angular outer edge 44, preferably beveled at the junction between the annular rib 26 and the peripheral region 23. The outer edge 44 defines the rear end 20 of the capsule 1. The central stud 30 is axially set back towards the interior of the body 4 in relation to the outer edge 44.

Preferably, the peripheral region 23 has a reinforcing over thickness along the outer edge 44, so as to reinforce the outer edge 44. The peripheral region 23 has for example a thickness that increases from the side wall 10 towards the outer edge 44.

The internal shoulder 14 is annular and protrudes radially from the side wall 10 towards the interior of the body 4. It is set back axially towards the interior of the body 4 in relation to the front end 22 of the body 4 and the annular flange 16.

The membrane lid 6 is fixed by its periphery to the inner shoulder 14 in a manner so that the membrane lid 6 is disposed in set back position axially towards the interior of the body 4 in relation to the front end 22 of the body 4. Preferably, the membrane lid 6 is set back in relation to the front end 22 of the body by a distance that is greater than 1 mm.

The membrane lid 6 closes the front end 22 of the body 4.

The membrane lid 6 includes an outlet filter 49 that is appropriate for allowing a pressurized fluid to pass while retaining the substance in the chamber 8. The filter 49 is made of porous filter paper, woven plastic material or perforated plastic film.

The membrane lid 6 further includes a membrane 50 that is impermeable to air and water lining the filter 49. The membrane 50 has lines of weakness 52, so as to ensure that the membrane 50 is liable to tear under the sole effect of the pressure of a liquid. In the example shown in FIGS. 1 and 3, the lines of weakness 52 form a cross. In the alternative, they form circles, arcs, or any other suitable form to allow optimal tearing of the membrane 50.

The filter 49 is positioned between the chamber 8 and the membrane 50. The filter 49 and the membrane 50 are joined to one another. The filter 49 and the membrane 50 are, for example in the form of a complex two-layer film.

The annular flange 16 extends radially outward towards the exterior from the side wall 10. The annular flange 16 defines the front end 22 of the body 4. The flange 16 has a free edge region 54. It does not support any inserted impermeable member or raised impermeable member that is deformable. As shown in FIGS. 1 to 3, the annular flange 16 is substantially planar.

The capsule 1 is intended to be placed in an extraction device 350, shown in FIGS. 4 and 5.

The extraction device 350 includes a hollow receiving member 352, defining a housing cavity 353 designed for receiving the capsule 1, and a support 354. It is suited to being maneuvered between an open configuration in which the receiving member 352 and the support 354 are mutually set apart from each other so as to introduce the capsule 1 in the receiving member 352, and a closed position, shown in FIG. 5, wherein the receiving member 352 and the support 354 are mutually close together, for injecting the extraction liquid into the capsule 1. In FIG. 4, the device 350 is shown in an intermediate configuration in which it is partially open, however not sufficiently open to allow the introduction of the capsule 1.

The housing cavity 353 has an inner side face 360, a housing cavity base 370 and a conduit 372 for supplying the extraction liquid opening on the housing cavity base 370, that is substantially centered and an opening 376 to introduce the capsule 1.

The inner side face 360 is rotationally symmetrical about a longitudinal axis Y. In the example shown, it is substantially frusto conical. When the capsule 1 is placed in the extraction device 350, the longitudinal axes X of the capsule 1 and Y of the housing cavity 353 substantially coincide.

The receiving member 352 has an annular rim 380 surrounding the opening 376.

The capsule 1 has an axial length that is sufficient in order for—in the closed configuration of the extraction device 350—the capsule 1 to be supported by its annular flange 16 against the support 354 and by its base 12 against the housing cavity base 370 along a closed annular line of contact 122, preferably defined on the peripheral region 23 along the outer edge 44 of the annular trench 28.

The capsule 1 is advantageously adapted to deform elastically under the effect of the axial compression force F in order to ensure sufficient contact between the base 12 and the housing cavity base 370.

Optionally the capsule 1 is adapted so that, under the effect of the axial compression force F, at least one annular zone 130 of the base 12 and/or of the side wall 10 of the capsule 1 will expand radially outward towards the exterior so as to ensure additional contact 128 with the side face 360 of the housing cavity 353, along a closed annular line of contact.

The extraction process of the capsule 1 by the extraction device 350 will now be described.

The capsule 1 is first placed in the device 350 in an open configuration, then the device 350 is maneuvered so as to move in the closed configuration.

During this movement to the closed configuration, the capsule 1 is supported by its annular flange 16 against the support 354 then the receiving member 352 axially presses on the base 12 of the capsule 1, so that the contact 122 is created, and the body 4 is deformed as a whole in a manner such that the contact 128 is created with the receiving member 352 of the device 350.

Once the device 350 is in the closed configuration, the extraction fluid is injected under pressure through the conduit 372. Under the effect of the pressure of the extraction fluid, the weakened areas 32 of the central region 24 of the base 12 break and the extraction fluid enters into the capsule 1.

The fluid pressure in the capsule 1 then increases and, under the effect of this pressure, the outlet membrane 50 tears. The fluid then escapes out of the capsule 1 by passing through the membrane lid 6 and being filtered by the filter 49.

Thanks to the invention, the base reinforced by an annular rib allows for the fabrication of the body of the capsule from a material that is relatively flexible and deformable without the base collapsing towards the interior of the capsule under the effect of the fluid pressure. The convexity of the base makes it possible to define a base that is durable and elastically deformable, with a large chamber volume that allows for loading a larger quantity of substance into the capsule. The rib defining an annular trench in the outer surface enables the improvement of the injection of the extraction liquid into the capsule. The presence of an annular flange increases the stability of the capsule on the support of the extraction device.

The capsule has a cup shaped body whose base is impermeable to air and water, the body being closed by a membrane lid that is impermeable to air and water. The impermeability of the capsule makes it possible to keep the substance protected and away from air and moisture. The membrane lid has a membrane that tears under the effect of fluid under pressure thereby enabling the appropriate opening of the membrane lid from a predetermined pressure level, with a delayed effect that is beneficial for obtaining a good quality extraction. The membrane lid that is set back axially towards the interior of the body avoids any interference with the support of the extraction device prior to the opening of the membrane, and thereby enables the controlled opening of the capsule. The membrane combined with a filter makes it possible to ensure the extraction of the substance under satisfactory pressure conditions with the effective retention of the substance inside the capsule. The membrane lid provided in the form of a complex film facilitates the manufacture of the capsule at a low cost.

The variants of the capsule illustrated in FIGS. 6 and 7 differ from that shown in FIGS. 1 to 3 in that the edge region 54 of the annular flange 16 is inclined towards the front of the capsule 1. As shown in FIG. 6, the annular flange 16 is curved forward towards the front of the capsule 1. As shown in FIG. 7, the annular flange 16 is frusto conical flaring towards the front.

As illustrated in FIGS. 8 and 9, during the closing of the extraction device 350, under the effect of the pressing force exerted by the support 354, the annular flange 16 is deformed by flattening.

Such a flange 16 allows for ensuring and strengthening the contact 122 between the base 12 of the capsule 1 and the housing cavity base 370 at the closing of the device 350, while being deformable in order to enable the closure of the extraction device 350.

The capsule 1000 according to a second embodiment of the invention, shown in FIGS. 9 to 21 includes, as shown in FIGS. 9 and 10, a hollow body 1004 and an outlet membrane lid 1006 together defining an interior chamber 1008 containing a substance (not shown) for the preparation of a beverage.

The body 1004 has a generally cup shaped form and is impermeable to air and water. It includes an outer side wall 1010, a base 1012 closing a rear end 1020 of the body 1004, and an annular flange 1016 surrounding an open front end 1022 of the body 1004.

The outer side wall 1010 and the base 1012 are formed integrally as one piece and made of a first plastic material that is impermeable to air and water. The first plastic material is chosen for being inert in relation to the substance contained in the capsule 1000. Preferably, said first material is translucent and is not colored in the mass, in order to avoid the diffusion of the color in the substance. Typically, the second plastic material is polyamide. The polyamide does not interfere with foodstuffs and effectively constitutes a high performance barrier to air and water.

Preferably, the annular flange 1016 is composed of a second plastic material different from the first plastic material. The second plastic material is preferably chosen for being a low cost material. The latter not being in contact with the substance, its properties vis-à-vis the substance are not taken into account in the selection of the second material. Typically, the second plastic material is polyurethane, which is an inexpensive material.

Preferably, the first and second plastic materials are compatible materials, that is to say, materials suitable for polymerization with each other.

Thus, it is possible to produce capsules 1000 at reduced cost. These capsules being meant to be produced in very large quantities, it allows for obtaining substantial savings.

Preferably, the second material is colored in the mass. Thus, it is possible to color differently, the annular flanges 1016 of capsules 1000 containing various substances, in a manner so as to easily distinguish a capsule 1000 containing a first substance from another capsule 1000 containing a second substance, that is different from the first.

The outer side wall 1010 extends from the base 1012 along a longitudinal axis X until the front end 1022 of the body 1004.

The outer side wall 1010 is substantially rotationally frusto conical about the longitudinal axis X. It is rigid. It has an inner surface 1010 a, oriented to face the chamber 1008, and an outer surface 1010 b, opposite to the inner surface 1010 a.

The base 1012 includes a peripheral region 1023 and a central region 1024.

The peripheral region 1023 is rigid. It is rounded and extends radially inward towards the interior and axially towards the rear from the outer side wall 1010, and has a concavity facing towards the interior of the body 1004. It thus extends from the outer side wall 1010 up to the rear end 1020 of the body 1004. The rear end 1020 is typically a closed line, for example a circle.

The central region 1024 returns axially towards the interior of the chamber 1008 from the peripheral region. The central region 1024 thus defines in the base 1012 a recess 1028 on the exterior of the body 1004.

The central region 1024 includes a tubular outer portion 1036 extending axially towards the interior of the chamber 1008 from the peripheral region 1023, a bottom portion 1038 extending radially towards the interior from the inner end of the external portion 1036 and closing the recess 1028, and a central inner portion 1034 protruding outward towards the exterior from the bottom portion 1038.

The inner portion 1034 defines a hollow center stud 1030 in the recess 1028. It thus has an annular shape. The outer portion 1036, the bottom portion 1038 and the inner portion 1034 define an annular rib 1026 in the central region 1024.

The bottom portion 1038 includes at least one weakened area 1032 provided so as to rupture under the effect of a fluid under pressure. Preferably, the or each weakened area is provided so as to rupture at a pressure of the fluid pressurized to between 1 and 3 bars.

The or each weakened area 1032 is provided, for example, in the form of areas of reduced thickness, as shown in FIG. 12. As long as the or each weakened area 1032 is not broken, the base 1012, and by extension the whole body 1004, is impermeable to air and liquids.

In the example illustrated in FIG. 11, the weakened area is defined in the periphery of the bottom portion 1038, at the junction between the bottom portion 1038 and the outer portion 1036. The area of weakness is in the shape of a circular arc. The circular arc preferably extends over at least 270°.

The shape of the inner portion 1034 determines the axial shearing force generated by a liquid under pressure present in the recess 1028.

In the embodiment in FIGS. 9 to 15, the inner portion 1034 has a frusto conical shape, which widens from the rear towards the front of the capsule 1000, and protrudes outward towards the exterior.

Alternatively, the inner portion 1034 is extending in a radial plane. At a determined pressure of the fluid present in the recess 1028, a planar inner portion 1034 induces a shearing force higher than the inner portion protruding towards the exterior.

The body 1004 also includes longitudinal ribs 1042 for stiffening of the outer side wall 1010 and radial ribs 1044 for stiffening of the base 1012.

Each longitudinal rib 1042 extends longitudinally along the outer side wall 1010, preferably, as shown, along the inner surface 1010 a. Thus, the longitudinal ribs are adapted so as to promote the emulsion between the pressurized fluid and the substance contained in the chamber 1008. As a variant, each longitudinal rib 1042 extends along the outer surface 1010 b.

Each radial rib 1044 extends radially between the outer portion 1036 and the peripheral region 1023. The radial ribs 1044 stiffen the base 12 and thus promote the generation of shearing forces induced by the pressure of the pressurized fluid directly on the or each area of weakness 1032. In the example shown in FIGS. 10 to 15, each radial rib 1044 extends as an extension of a longitudinal rib 1042.

The annular flange 1016 extends radially outward towards the exterior, from an annular inner rim 1046 until an annular outer rim 1048, from the outer surface 1010 b of the outer side wall 1010. It defines the front end 1022 of the body 1004. It does not support any inserted impermeable member or raised impermeable member that is deformable. Preferably it is substantially planar. The outer annular rim 1048 is free.

As visible in the detail shown in FIG. 13, the outer surface 1010 b of the outer side wall 1010 defines, in the vicinity of the front end 1022 of the body 1004, an annular recess 1049 defining a shoulder 1050 and a groove 1052 connecting the annular flange 1016 at the outer side wall 1010.

The shoulder 1050 is set back towards the rear in relation to the front end 1022. It extends radially and in parallel to the front end 1022, between an inner end 1054 and an outer end 1056.

The groove 1052 is formed in the shoulder 1050 and protrudes longitudinally towards the rear from the inner end 1054 of the shoulder 1050.

The annular flange 1016 includes an annular protuberance 1058 protruding longitudinally from the inner annular rim 1046 in the groove 1052. The protuberance 1058 cooperates with the groove 1052 so as to strengthen the connection of the annular flange 1016 to the outer side wall 1010.

Thus, a portion of the outer side wall 1010 extends between the annular flange 1016 and the chamber 1008, which thereby prevents the substance from coming into contact with the second material.

Returning to FIG. 1, the membrane lid 1006 is attached by its periphery to the outer side wall 1010 and on the annular flange 1016. The membrane lid 1006 thus closes the front end 1022 of the body 1004.

The membrane lid 1006 includes an outlet filter 1060 that is appropriate for allowing a pressurized fluid to pass while retaining the substance contained in the chamber 1008. The filter 1060 is made of porous filter paper, woven plastic material or perforated plastic film. Preferably, the filter 1060 is, as shown, in set back position from the front end 1022, towards the chamber 1008, and is fixed at its periphery to the inner surface 1010 a of the outer side wall 1010. The filter 1060 is, for example, set back in relation to the front end 1022 by a distance of between, 1 and 1.5 mm.

The membrane lid 1006 further includes a membrane 1062 that is impermeable to air and water lining the filter 1060. Preferably, the membrane 1062 is fixed, for example welded, to the annular flange 1016. The membrane 1062 extends along the front end 1022 of the body 1004. The membrane 1062 enables maintaining the substance in an inert atmosphere, in a manner so as to avoid oxidation of the substance.

The membrane 1062 is peelable, that is to say that, it can be easily detached from the body 1004. For this purpose, it includes a tab 1064 extending radially towards the exterior from the annular flange 1016, in order to allow a user to easily remove the membrane 1062 before use of the capsule in 1000 in an extraction device.

Optionally, the membrane 1062 has lines of weakness (not shown) such that the membrane 1062 is capable of tearing under the sole effect of the pressure of a liquid. Thus, in the event where a user would have forgotten to remove the membrane 1062 before inserting the capsule 1000 in an extraction device, the extraction can still be carried out normally, without damage to the extraction device.

The filter 1060 is positioned between the chamber 1008 and the membrane 1062. The space between the filter 1060 and the membrane 1062 is preferably filled with an inert gas, typically with nitrogen.

The capsule 1000 is shown in FIG. 14 inserted in a beverage extraction device 1100. This device 1100 is similar to the extraction device 350 described above. Similar elements are designated by the same reference numerical signs. It should be noted that the capsule 1000 is adapted in order for the annular edge 380 to come in contact with the annular flange 1016 when the extraction device 1100 is in the closed configuration.

A variant of the extraction device 1100 is shown in FIG. 15. In this figure, it will be observed that the conduit 372 for supplying the extraction liquid is radially offset in relation to the longitudinal axis Y. Thus, the capsule 1000 is also adapted to be used in beverage extraction devices where the arrival of pressurized liquid into the receiving housing cavity 353 does not occur at the center of the housing cavity 353.

A variant of the capsule 1000 is presented in FIGS. 16 and 17.

In this variant, the inner portion 1034 has a hemispherical form with concavity oriented towards the interior of the body 1004. This shape is adapted so as to allow the rupture of the weakened area 1032 at higher pressures in the event of the inner portion 1034 having a frusto conical shape.

The annular flange 1016 is not connected to the outer surface 1010 b of the outer side wall 1010, but to a front annular face 1066 of the outer side wall 1010. Said annular front face 1066 defines a groove 1068 protruding longitudinally towards the rear and with which the protuberance 1016 of the annular rim 1058 cooperates in order to strengthen the connection of the annular rim 1016 with the outer side wall 1010.

The inner surface 1010 a of the outer side wall 1010 defines an annular internal shoulder 1070 extending in a radial plane and being oriented towards the front. The internal shoulder 1070 is set back axially towards the interior of the body 1004 in relation to the front end 1022 of the body 1004 and the annular flange 1016. The internal shoulder 1070 is adapted to support the membrane lid 1006.

The internal shoulder 1070 being set back in relation to the front annular face 1066, the substance is thus not in contact with the second material forming the annular flange 1016.

Similarly as in the first embodiment, the membrane lid 1006 is formed by a complex two layer film including the filter 1060 and the membrane 1062. This complex film is fixed at its periphery to the inner shoulder 1070 such that the membrane lid 1006 is in set back position axially towards the interior of the body 1004 with respect to the front end 1022 of the body 1004. Preferably, the membrane lid 1006 is set back in relation to the front end 1022 of the body 1004 by a distance that is greater than 1 mm.

Other variants of the capsule 1000 are shown in FIGS. 18 to 22.

In the variant shown in FIG. 18, the bottom portion 1038 includes a plurality of weakened areas 1032, each being formed by two lines of weakness intersecting in a manner so as to form a cross. In the example shown, the weakened areas 1032 are four in number. As a variant, the number of weakened areas 1032 is different.

In the variant shown in FIG. 18, the bottom portion 1038 includes a plurality of weakened areas 1032, each formed by a closed circular line of weakness, each bounding a disk not including the inner portion 1034. In the example shown, the weakened areas 1032 are three in number. As a variant, the number of weakened areas 1032 is different.

In the variant shown in FIG. 20, the bottom portion 1038 includes two weakened areas 1032, each having the shape of a serrated semi circle and extending to the periphery of the bottom portion 1038, along the junction with the outer portion 1036.

The base 12 further includes two ribs 1080 for strengthening the central region 1024. Each rib 1080 extends longitudinally between the tubular portion 1026 and the peripheral rim 1030. Each rib 1080 is interposed between the two weakened areas 1034. In the example shown, the ribs 1080 are thus diametrically opposite to one another.

These ribs 1080 are designed to concentrate the shearing forces due to the force exerted by the fluid under pressure on the base 1012 in the extraction device 1100 on the weakened areas 1034.

In the variant shown in FIG. 21, the bottom portion 1038 includes three weakened areas 1032, each being formed by a closed line bounding a crescent with the longer side extending along the outer portion 1036.

The base 1012 also includes ribs 1080 for reinforcing the central region 1024. There are three of these ribs 1080 present here and each is sandwiched between two weakened areas 1032.

Finally, in the variant shown in FIG. 22, the bottom portion 1038 includes one single weakened area 1032 constituted by a closed circular line extending along the outer portion 1036.

The method for manufacturing the capsule 1000 will be briefly described, with reference to FIG. 10.

As an initial step, the first plastic material is cast, for example injected, in a mould, to form the base 1012 and the outer side wall 1010. Then, as an second step, the second plastic material is in turn cast into the mould, in a manner so as to form the annular flange 1016.

The first and second plastic materials being compatible materials, they bind chemically. In particular, diffusion of a part of the molecules of the first material into the second material occurs and vice versa. Thus, the formation of a thin layer takes place in which the two materials are mixed and the two materials are thus intimately linked with each other.

Thanks to the invention, the portion of the body of the capsule in contact with the substance is formed of a material that is inert in relation to the substance, which thereby makes it possible to maintain the substance under optimal conditions, without risk of degradation of the substance by oxidation or by toxic elements contained in the material in contact with the substance.

Furthermore, the fact that the first plastic material is not colored in the mass ensures reduction of the likelihood of migration of toxic elements from the capsule to the substance.

Finally, the fact of using a second material for the annular flange ensure the reduction of the cost of manufacturing the capsule and in addition enables, through the coloring of the second material, the easy identification of the substance contained in the chamber of the capsule without risk of migration of the pigment into the substance, the latter not being in contact with the second material.

It should be noted that the description given here above is by no means restrictive, and that the characteristic features of different variants and different embodiments may be combined with each other without departing from the scope of the invention. 

1. A capsule for extraction of a beverage under pressure, comprising: a body in cup shaped form and a membrane lid together defining a chamber containing a substance for the preparation of a beverage, the body comprising: an outer substantially frusto conical side wall and a base formed integrally as one piece with an outer side wall and closing the outer side wall at a rear end of the body, the membrane lid closing the outer side wall at a front end of the body, wherein the capsule being adapted so as to be disposed in an extraction device in a manner such that an extraction liquid under pressure enters into the capsule through the base and exits from it through the membrane lid, wherein the base comprises: a peripheral region defining a rear end of the body, and a central region returning towards the interior of the capsule in relation to the rear end while defining a recess on the exterior of the body, wherein the central region comprising at least one weakened area which is intended to break at least partially under the pressure of a pressurized liquid.
 2. The capsule according to claim 1, wherein the central region further comprises a bottom portion and a central stud protruding from the bottom portion towards the exterior.
 3. The capsule according to claim 2, wherein the central region further comprises an annular rib protruding towards the interior of the body, the recess having the shape of an annular trench on the exterior of the body.
 4. The capsule according to claim 1, wherein the central region further comprises a flat bottom portion axially closing the recess.
 5. The capsule according to claim 2, wherein the weakened area is formed in the bottom portion.
 6. The capsule according to claim 5, wherein the central region further comprises a tubular outer portion extending axially towards the interior of the chamber from the peripheral region, the weakened area being formed at the junction between the bottom portion and the outer portion.
 7. The capsule according to claim 1, wherein the base further comprises at least one rib for reinforcing the central region.
 8. The capsule according to claim 1, wherein the body further comprises at least one radial rib for stiffening the peripheral region.
 9. The capsule according to claim 1, wherein prior to the rupture of the weakened area, the base and the outer side wall of the body are impermeable to air and liquids.
 10. The capsule according to claim 2, wherein the central stud has a frusto conical shape.
 11. The capsule according to claim 2, wherein the central stud has a hemispherical shape.
 12. The capsule according to claim 1, wherein the membrane lid comprises a filter and a membrane.
 13. The capsule according to claim 12, wherein the filter is set back from the front end of the body, towards the chamber, and the membrane extending along the front end.
 14. The capsule according to claim 13, wherein the space between the filter and the membrane is filled with nitrogen.
 15. The capsule according to claim 12, characterized in that wherein the membrane is peelable.
 16. The capsule according to claim 1, wherein the outer side wall and the base are formed of a first plastic material, and the body comprises an annular flange extending radially outward towards the exterior from the outer side wall and defining the front end of the body, wherein said annular flange being formed of a second plastic material, different from the first plastic material.
 17. The capsule according to claim 1, wherein the weakened area is adapted so as to rupture from the pressure of the liquid being pressurized to between 1 and 3 bars.
 18. A system comprising a capsule according to claim 1 and an extraction device having a housing cavity designed for receiving the capsule, a support, and a conduit for supplying the pressurized extraction liquid. 